GIFT  OF 


DEPARTMENT  OF  AGRICULTURE 


FOREST  PRODUCTS  LABORATORY 


REPORT  PREPARED  FOR 

THE  COMMISSION  OF  THE  UNITED  STATES  OF  AMERICA  TO 
THE  BRAZIL  CENTENNIAL  EXPOSITION 


For  Distribution  at  the  Brazil  Centennial  Exposition 
1922-1923 


WASHINGTON 

GOVERNMENT  PRINTING  OFFICE 
1922 


DEPARTMENT  OF  AGRICULTURE 


FOREST  PRODUCTS  LABORATORY 


Supplementing  Exhibit 

of  the 
UNITED  STATES  FOREST  SERVICE 

at  the 

BRAZIL  CENTENNIAL  EXPOSITION 

Rio  de  Janeiro,  Brazil 

1922-1923 


HERBERT  A.  SMITH 

United  States  Forest  Service 


FOREST  PRODUCTS  LABORATORY. 


A    BRIEF   ACCOUNT   OF   ITS  WORK   AND   AIMS. 

The  Forest  Products  Laboratory  is  a  unit  in  the  Branch  of  Research  of 
he  Forest  Service,  United  States  Department  of  Agriculture.  It  is 
ocated  at  Madison,  Wis.,  and  is  conducted  in  cooperation  with  the 
Jniversity  of  Wisconsin. 

For  several  years  after  its  establishment,  in  1910,  it  was  the  only 
nstitution  of  its  kind  in  the  world  conducted  with  the  object  of  turning 
he  searchlight  of  research  upon  wood  and  its  uses  and  making  the  infor- 
nation  thus  obtained  available  to  the  public. 

PUBLIC   SERVICE. 

SCOPE  OF  ACTIVITIES. 

The  purpose  of  the  Forest  Service  in  the  administration  of  the  Forest 
'roducts  Laboratory  is  to  conserve  American  forests  by  developing  the 
nost  economical  methods  of  converting  standing  trees  into  finished  prod- 
cts.  The  purpose  is  also  to  make  the  growing  of  timber  more  profita- 
»le  by  increasing  the  possibilities  in  the  utilization  of  both  used  and 
nused  species.  The  Laboratory  seeks  to  develop  not  only  new  and  more 
indent  processes,  but  to  find  ways  of  utilizing  material  which  would 
therwise  be  wasted,  to  find  new  uses  for  old  materials  and  new  materials 
or  old  uses.  In  a  word,  the  aim  is  to  render  practical  assistance  to  the 
tianufacturers  and  users  of  wood  and  wood  products  and  at  the  same  time 
o  promote  forest  conservation  and  the  practice  of  forestry. 

Every  American  industry  and  class  of  consumers  which  uses  or  grows 
•ood  or  any  other  product  of  the  forest  may  thus  be  a  beneficiary  of  the 
•ork  done  at  the  Laboratory.  Every  such  industry,  class  of  consumers, 
nd  timber  producers  is  a  potential  cooperator  in  the  Laboratory's  work, 
ts  objects  are  sought  not  only  through  experiments  conducted  at  the 
.aboratory  but  also  through  the  detail  of  its  men  to  work  on  important 
roblems  in  the  mills  and  factories  and  the  receiving  of  representatives  of 
he  industries  at  the  Laboratory  to  work  beside  its  scientific  men. 

VALUE   OF    WORK. 

The  value  of  this  work  has  already  made  itself  apparent.     The  reduc- 
on  of  waste,  the  better  utilization  of  the  products  of  the  tree,  the  utiliza- 
of  species  hitherto  wasted,  the  added  life  given  to^many  kinds  of 

3 

50056? 


£RODU£TS   LABORATORY. 

wood  products  by  more  efficient  preservative  methods,  the  reduction  02 
the  degrade  in  lumber  by  efficient  dry-kiln  methods,  and  many  othei 
savings  are  an  enormous  help  in  conserving  the  timber  supply. 

RESULTS  AVAILABLE  TO   PUBLIC. 

The  value  of  the  Forest  Products  Laboratory  to  any  particular  wood- 
using  industry  or  class  of  consumers  depends  to  a  very  large  extent  upor 
the  use  which  that  industry  makes  of  it.  It  is  a  Government  institutior 
supported  mainly  by  Government  appropriations,  and  its  advice  anc 
suggestions  are  to  be  had  for  the  asking.  It  presents  an  opportunity  foi 
every  manufacturer,  user,  and  timber  grower  to  supplement  the  informa 
tion  obtained  by  experience  and  hard  knocks  with  technical  data  obtainec 
through  scientific  research. 

PLACE  IN  FOREST  CONSERVATION. 

The  work  of  the  Laboratory  is  of  direct  value  to  those  engaged  ir 
timber  production.  To  a  very  large  extent  the  kinds  and  sizes  of  forest 


trees  which  should  be  grown  and  the  purposes  for  which  they  should  be 
produced  are  dependent  on  the  mechanical,  physical,  and  chemical  proper- 
ties of  their  wood  and  the  uses  to  which  they  can  most  profitably  be  put 
In  the  administration  of  the  National  Forests  and  of  privately  owned 
timberlands,  in  the  activities  of  the  State  forestry  depaitments,  and  in! 
the  instruction  given  by  the  forest  schools  the  results  secured  by  the 
Laboratory  play  an  important  part.  By  reducing  the  present  waste  ofi 
three-fourths  of  every  tree  cut  and  making  possible  the  most  efficient 
utilization  of  the  one-fourth  used  they  are  contributing  in  a  very  essential 
way  to  forest  conservation  and  to  profitable  timber  production.  Through 
its  forest  products  research  the  Forest  Service  supplements  its  efforts  to 
bring  about  the  growing  of  timber  by  information  which  should  make 
possible  the  most  complete  and  effective  utilization. 


FOREST  PRODUCTS  LABORATORY.  5 

ORGANIZATION   FOR  RESEARCH. 

COORDINATED   RESEARCH. 

Research  is  increasingly  effective  in  proportion  as  it  is  carefully  planned 
md  executed.  At  the  beginning  of  each  year  a  program  covering  as  nearly 
is  practicable  the  work  of  the  Laboratory  for  the  ensuing  year  is  con- 
idered  and  approved.  Individual  initiative  and  responsibility  are  given 
he  widest  possible  opportunity,  but  at  the  same  time  the  work  of  different 
nen  is  so  coordinated  by  an  interchange  of  ideas  among  the  different 
sections,  and  other  means,  that  duplication  is  avoided  and  cumulative 
•esults  are  obtained. 

ORGANIZATION   OF  THE  LABORATORY. 

The  Laboratory  is  in  charge  of  a  director,  an  assistant  director,  and  a 
>taff  comprised  of  the  heads  of  the  different  research  and  administrative 
sections.  In  each  section  are  men  of  broad  general  experience  with  wood 


and  knowledge  of  its  characteristics,  and  other  specialists  in  various  wood 
uses,  who  devote  their  whole  time  to  the  study  of  special  problems.  These 
men  are  recruited,  in  accordance  with  the  regulations  of  the  Civil  Service 
Commission,  from  the  professions  of  engineering,  chemistry,  forestry,  and 
pathology. 

The  work  of  the  Laboratory  is  distributed  among  the  following  technical 
sections : 

Timber  mechanics. — Strength  of  wood  and  manufactured  articles. 

Timber  physics. — Experimental  and  applied  kiln  drying,  physical  prop- 
erties, identification,  and  structure  of  wood. 

Wood  preservation. — Wood  treatments,  glues,  and  laminated  construc- 
tion. 

Pulp  and  paper. — Manufacturing  methods  and  suitability  of  various 
woods  for  pulp,  paper,  and  special  products. 

Derived  products. — Chemical  properties  and  uses  of  wood  and  chemical 
wood  products,  such  as  turpentine,  alcohol,  acetic  acid,  etc. 


ft  FOREST  PRODUCTS  LABORATORY. 

Industrial  investigations. — Methods  and  practices  in  the  lumber  and 
other  wood-using  industries,  grades,  specifications,  and  mill  scale  studies. 

Pathology  (in  cooperation  with  the  Bureau  of  Plant  Industry). — Decay 
of  timber,  molds,  stains  in  manufactured  wood  products,  and  antiseptic 
properties  of  wood  preservatives. 

TIMBER  MECHANICS. 

N. 

Knowledge  of  the  mechanical  properties  of  woods  and  wood  products  is 
essential  for  their  intelligent  and  economic  use,  whether  in  the  factory,  on 
the  farm,  in  the  home,  on  the  railroad,  in  the  mine,  or  in  the  air.  Thus 
development  of  the  airplane  and  progress  in  many  other  lines  depend 
in  a  large  measure  on  accurate  information  as  to  the  strength,  toughness, 
elasticity,  and  other  mechanical  properties  which  determine  the  suitability 
of  different  woods  for  various  purposes.  To  supply  this  information,  over 
500,000  mechanical  tests  have  been  made,  as  nearly  as  possible  under 
standardized  conditions,  so  that  the  tests  made  for  a  single  purpose  will 
have  the  broadest  application  and  will  serve  for  many  uses. 

STRENGTH   OF   VARIOUS   SPECIES. 

Data  from  tests  of  small  clear  specimens  are  now  available  in  150  species 
of  woods  grown  in  the  United  States,  as  well  as  data,  in  some  cases 
meager,  in  some  cases  fairly  complete,  on  about  60  species,  principally 
from  South  America  and  the  Philippines.  These  data  are  of  particular 
value  in  comparing  the  properties  of  the  different  species,  in  finding 
substitutes  for  the  scarcer  and  higher-priced  woods,  in  selecting  species 
for  particular  uses,  and  in  establishing  correct  working  stresses.  The 
results  of  these  tests  on  small  clear  specimens  also  furnish  definite 
information  on  the  variability  of  wood  and  show  the  necessity  of  grading 
timber  for  all  uses  where  strength  is  of  prime  importance. 

A  large  number  of  tests  have  also  been  made  on  full-size'd  timbers, 
such  as  bridge  stringers,  factory-building  timbers,  and  car  sills.  These 
tests  have  demonstrated  the  influence  of  defects,  such  as  knots,  shakes, 
and  checks,  on  strength ;  and,  altogether  with  the  results  of  tests  on  small 
clear  specimens,  furnish  the  basis  for  the  establishment  of  grading  rules 
and  correct  working  stresses  for  structural  timbers. 

Tests  have  been  made  on  plywood  to  determine  the  strength  of  different 
combinations  of  species,  the  effect  of  increasing  the  number  of  plies,  and 
the  effect  of  varying  the  ratio  of  core  thickness  to  total  panel  thickness. 
Some  data  are  also  available  on  factors  affecting  warping,  on  strength 
of  fastenings  for  plywood,  on  the  efficiency  of  joints  in  plywood,  and  on 
the  strength  in  tension.  Information  on  such  points  as  these  places  the 
Laboratory  in  a  position  to  assist  users  and  manufacturers  of  plywood 
and  veneer  products  in  solving  problems  encountered  in  developing  new 
uses  for  these  products  in  the  various  industries. 


FOREST  PRODUCTS  LABORATORY. 


The  largest  of  the  testing  machines,  shown  here  in  the  process  of  erection,  is  capable  of  exerting  a  force  of  a 
million  pounds  and  can  test  to  destruction  wooden  columns  30  feet  long  and  a  foot  square. 


FOREST  PRODUCTS  LABORATORY. 


The  drum  testing  machine,  developed  by  the  Laboratory  to  simulate  the  hazards  of  transportation,  has 
become  standard  for  shippers,  packers,  and  manufacturers.  The  boxes  shown  are  packed  with  electric- 
light  bulbs.  Four  thousand  dollars'  worth  of  bulbs  were  furnished  by  the  electric  companies  concerned 
for  this  series  of  tests  to  develop  a  better  container. 


FOREST  PRODUCTS  LABORATORY. 


Some  of  the  strength-testing  machines,  such  as  the  one  at  the  right,  are  employed  chiefly  in  determining 
the  strength  properties  of  native  woods,  using  small,  clear  specimens  like  those  on  the  truck.  Other 
machines  are  rigged  up  to  test  wooden  parts.  A  newly  designed  airplane  wing  rib  is  just  being  placed  in 
the  machine  second  in  line. 

11958—22 2 


10 


FOREST  PRODUCTS  LABORATORY. 


Furniture  and  vehicle  factories  are  concerned  in  the  research  of  the  Laboratory  to  reduce  losses  in 
the  steam  bending  of  stock.  To  bend  a  heavy  wheel  rim,  such  as  is  shown,  without  fracture,  requires 
a  careful  preliminary  conditioning  treatment. 


FOREST   PRODUCTS   LABORATORY.  II 

TESTS  ON   SHIPPING   CONTAINERS. 

The  results  of  tests  on  containers  are  of  particular  interest  to  all 
shippers,  box  manufacturers,  and  transportation  companies,  and  are 
also  of  great  importance  to  the  public  in  general.  The  damage  due  to  the 
failure  of  containers  in  transportation  amounts  annually  to  many 
millions  of  dollars.  There  are,  in  addition,  large  losses  due  to  improper 
packing.  All  of  the  work  done  at  the  Laboratory  in  this  field  tends 
directly  to  reduce  these  enormous  losses,  which  are  ultimately  paid  by 
the  consumer.  A  considerable  amount  of  fundamental  data  relating 
to  the  construction  of  boxes  and  crates  has  been  obtained  which  finds 
direct  application  in  the  redesign  of  faulty  containers  and  in  the  develop- 
ment of  new  containers.  It  is  frequently  possible  to  redesign  a  container 
so  as  to  reduce  the  amount  of  material  required,  to  save  shipping  and 
warehouse  space,  and  at  the  same  time  to  obtain  greater  serviceability. 

DRUM  TESTS. 

Revolving-drum  tests,  together  with  drop  and  compression  tests  of 
boxes  loaded  with  either  actual  or  dummy  contents,  have  been  used  in 
determining  the  characteristic  weakness  of  the  various  types  of  con- 
tainers. The  Forest  Products  Laboratory  standard  drum  is  14  feet  in 
diameter  and  can  accommodate  packages  up  to  1,000  pounds  in  weight. 
It  is  fitted  with  hazards  so  arranged  that  the  container  under  test  follows 
a  regular  cycle  of  drops  which  simulate  those  received  in  actual  trans- 
portation. The  field  for  this  work  is  very  large,  and  much  remains  to  be 
done  in  order  to  develop  fundamental  relations  between  the  weight  and 
the  nature  of  the  commodity,  the  type  of  box  to  be  used,  and  the  thick- 
ness of  the  bottom,  side,  and  end  boards. 

TESTS  OF  MANUFACTURED  ARTICLES. 

Tests  on  vehicle  and  implement  parts,  airplane  parts,  doors,  and  other 
articles  manufactured  of  wood  are  made  primarily  to  demonstrate  the 
fitness  of  substitute  species,  to  develop  or  improve  designs,  and  to  obtain 
more  economical  and  efficient  use  of  wood.  The  limitations  and  possibili- 
ties of  splices  and  laminated  construction  are  being  studied  with  a  view 
to  conserving  lumber  through  the  increased  use  of  small  pieces  and  low 
grades.  This  should  make  possible  the  use  of  smaller  trees,  which  can 
be  grown  in  comparatively  short  periods,  in  short,  the  character  of 
material  on  which  the  country  will  have  to  depend  very  largely  in  the 
future  and  which  can  be  grown  most  profitably. 


12 


FOREST  PRODUCTS  LABORATORY. 


TIMBER  PHYSICS. 

KILN    DRYING. 

A  knowledge  of  the  physical  properties  of  wood  is  of  importance  to 
almost  every  industry  using  wood  and  is  essential  in  kiln  drying,  impreg- 
nation with  preservatives,  distillation,  and  other  treatments.  These 
physical  properties  include  density,  shrinkage,  transfusion  of  moisture, 
hygroscopicity,  specific  heat,  heat  conductivity,  heat  of  absorption  of 
water  in  wood,  and  permeability  of  wood  by  liquids  and  gases. 

It  is  often  necessary  for  financial  reasons  to  reduce  the  time  required 
properly  to  season  wood  by  open-air  drying.  Moreover,  for  many  pur- 
poses it  is  desirable  to  dry  the  wood  more  thoroughly  than  is  possible  in 
the  open  air  and  to  employ  conditions  which  will  reduce  its  hygroscopicity, 
or  tendency  to  shrink  or  swell.  For  these  reasons  dry  kilns  are  almost 
universally  employed  for  high-grade  lumber,  and  frequently  even  for  the 
poorer  grades.  In  the  drying  of  hardwoods  it  is  estimated  that  about 
10  per  cent  of  the  material  dried  is  either  ruined  or  lowered  in  grade. 
Much  of  this  loss  could  be  avoided  by  proper  methods  and  kilns,  and  the 
present  results  might  be  greatly  improved  in  other  respects. 

ESTABLISHING    SCIENTIFIC   PRINCIPLES. 

The  Forest  Products  Laboratory  bases  all  its  kiln-drying  practice  on 
fundamental  studies  to  determine  the  principles  underlying  the  trans- 
fusion of  moisture  through  wood,  the  effect  of  changes  in  atmospheric 
conditions  upon  the  rate  of  transfusion,  the  effect  of  various  methods  of 
drying  and  of  various  drying  treatments  upon  the  properties  of  the  wood 
being  dried,  and  similar  studies. 

DRYING    SCHEDULES. 

A  comprehensive  series  of  experiments  is  being  conducted  to  determine 
the  proper  "drying  schedules"  for  all  important  commercial  woods. 
These  drying  schedules  will  show  the  proper  conditions  of  temperature 


FOREST  PRODUCTS  LABORATORY.  . 


'  1 1  ( I 


The  distiactive  feature  of  the  Forest  Service  water-spray  kiln  is  the  control  of  the  humidity  in  the  kiln 
and,  consequently,  the  drying  rate  of  the  lumber,  by  conditioning  the  air  with  sprays  of  water  whose 
temperature  is  carefully  regulated.  The  experimental  kiln  shown  is  drying  oak  bolster  stock,  which 
appears  white  because  of  the  end  dip  used  to  reduce  checking. 


14  FOREST  PRODUCTS  LABORATORY. 

and  humidity  to  obtain  best  results  in  drying,  and  they  will  cover  the 
entire  range  from  an  absolutely  green  condition  to  absolute  dryness.  A 
number  of  drying  schedules  have  already  been  published.  This  class 
of  work  has  direct  application  throughout  the  wood-using  industries. 

STEAM   BENDING. 

The  proper  steam  bending  of  heavy  wooden  parts,  such  as  artillery 
\vheel  rims,  presents  a  number  of  problems  on  which  the  Laboratory  has 
done  a  limited  amount  of  work  and  on  which  it  plans  to  do  much  more 
in  the  near  future.  The  proper  moisture  condition  of  the  stock,  the 
length  and  temperature  of  steaming  or  other  preliminary  treatment,  and 
the  mechanical  details  of  the  actual  bending  must  all  be  worked  out 
before  present  high  losses  in  this  process  can  be  overcome. 

IDENTIFICATION. 

The  accurate  identification  of  woods  is  important  not  only  in  the  in- 
vestigative work  of  the  Laboratory,  where  it  is  essential  that  the  kind  of 
wood  under  test  be  definitely  knowTi,  but  to  wood  users  generally. 
There  is  a  steadily  increasing  demand  in  the  various  industries  for  serv- 
ice of  this  character,  and  several  thousand  specimens  of  wood  are  an- 
nually identified  for  outside  concerns.  Microscopic  slides  and  photo- 
micrographs made  from  the  slides  have  been  prepared  for  practically  all 
American  woods  of  importance  and  are  available  for  study.  Authentic 
specimens  of  most  species  are  also  available. 


WOOD    PRESERVATION. 

PRESERVATIVES. 

The  amount  of  wood  in  the  form  of  railroad  ties,  mine  timbers,  posts, 
poles,  and  other  products  which  is  destroyed  each  year  by  decay  is 
estimated  at  from  one-half  to  three-quarters  of  a  billion  cubic  feet. 
It  is  therefore  important  to  devise  methods  of  treating  wood  with  pre- 
servatives that  will  reduce  this  waste  to  a  .minimum. 


FOREST  PRODUCTS  LABORATORY 


In  the  manufacture  of  water-resistant  plywood  with  casein  glue,  the  glue  is  applied  cold  to  the 
veneer  sheets  by  means  of  a  mechanical  glue  spreader.  The  sheets  are  then  placed  one  on  top 
of  another  in  a  press. 


i6 


FOREST  PRODUCTS  LABORATORY. 


The  life  of  railroad  ties  treated  with  preservatives  is  often  double  that  of  untreated  ties.  The 
illustration  shows  some  red-oak  ties  about  to  undergo  an  experimental  treatment  with  creosote 
in  the  pressure  cylinder.  Afterwards  they  will  be  placed  in  actual  service  in  one  of  the  test 
tracks  maintained  by  the  railroads  in  cooperation  with  the  Laboratory 


FOREST  PRODUCTS  LABORATORY.  1 7 

In  treating  operations,  the  cost  of  the  preservative,  such  as  creosote, 
zinc  chloride,  or  sodium  fluoride,  amounts  to  a  high  percentage  of  the 
total  cost.  Furthermore,  the  ultimate  success  of  any  treatment  is 
largely  dependent  upon  the  preservative  used.  Much  information  has 
already  been  obtained  concerning  the  preservatives  now  in  common 
use,  but  there  is  need  for  a  great  deal  of  further  study  with  the  object 
of  developing  new  preservatives  which  will  either  be  cheaper  or  more 
effective  than  present  preservatives  or  will  have  properties  fitting 
them  for  wider  use  or  for  special  purposes.  The  value  of  a  preservative 
is  not  considered  'established  until  it  has  had  a  thorough  trial  under 
actual  service  conditions. 

GLUES  FOR  PLYWOOD. 

In  connection  with  the  manufacture  of  plywood,  studies  have  been 
made  of  animal  glues,  such  as  those  made  from  hide,  bone,  and  other 
products;  and  standard  methods  of  testing  have  been  developed.  A 
suitable  "standard  glue"  for  aircraft  work  and  high-class  joint  work  in 
general  has  been  selected  and  samples  made  available  to  manufacturers 
and  users.  This  is  the  glue  adopted  as  standard  by  Army  and  Navy 
aircraft  bureaus. 

The  development  of  water-resistant  glues  of  several  types,  including 
casein  glues  and  blood-albumin  glues,  has  been  progressing  for  several 
years,  and  a  number  of  high-grade  glues  have  been  perfected.  Tests 
and  experiments  are  being  carried  forward  to  improve  these  glues  still 
more,  especially  in  their  resistance  to  moisture. 

LAMINATED   AND   BUILT-UP   PARTS. 

One  of  the  lines  of  investigation  to  be  taken  up  recently  is  the  deter- 
mination of  possibilities  and  best  practices  in  the  design  and  construction 
of  structural  members  built  up  of  small  pieces  glued  together.  These 
investigations  were  carried  out  intensively  on  aircraft  parts,  such  as 
wing  beams  and  struts,  when  the  success  of  the  aircraft  program  was 
threatened  by  a  sudden  shortage  of  suitable  material  in  the  required 
sizes.  The  knowledge  gained  is  being  applied  to  extensive  investigations 
of  the  use  of  laminated  and  built-up  construction  in  the  various  wood- 
using  industries  for  the  manufacture  of  such  articles  as  shoe  lasts,  hat 
blocks,  bowling  pins,  wagon  bolsters,  and  wheel  hubs. 

The  Laboratory  has  done  considerable  work  on  the  moisture  resistance 
of  various  wood  coatings,  and  a  very  efficient  aluminum  leaf  coating  has 
been  developed  which  affords  protection  against  moisture  over  long 
periods  of  storage.  Tests  are  now  in  progress  on  the  durability  of  these 
coatings.  Other  work  on  wood  finishes  is  contemplated. 


l8  FOREST  PRODUCTS  LABORATORY 


PULP  AND   PAPER. 

The  constantly  decreasing  supply  of  suitable  pulp  woods  and  the 
ever-increasing  demand  for  paper  of  all  kinds,  especially  newsprint 
paper,  have  combined  to  produce  so  serious  a  situation  that  investiga- 
tions into  methods  of  conserving  the  supply  of  pulp  wood  and  increasing 
the  production  of  paper  are  of  paramount  importance. 

PROCESSES  OF  PULP  AND  PAPER  MAKING. 

The  Laboratory  is  conducting  experiments  on  methods  of  making 
wood  pulp  and  has  already  developed  several  important  improvements 
in  the  standard  chemical  processes. 

A  very  important  field  of  research  lies  in  determining  the  suitability 
of  various  little-used  woods  as  substitutes  for  those  most  commonly  used. 
Practically  all  available  species  which  give  promise  of  suitability  are 
being  investigated,  and  proper  methods  of  grinding  or  cooking  of  most 
of  the  important  ones  have  already  been  worked  out. 

UTILIZATION   OF    WASTE- 

Studies  of  waste  utilization  in  the  pulp  and  paper  industry  have  been 
in  progress  for  some  time  along  a  number  of  distinct  lines.  For  example, 
feasible  methods  of  turning  sawmill  waste,  such  as  slabs,  into  pulp  have 
been  determined.  The  use  of  a  certain  percentage  of  spent  tanbark  in 
the  manufacture  of  roofing  felts  has  been  investigated  and  a  method 
developed  whereby  what  was  formerly  a  waste  of  the  tanning  industry 
is  now  in  profitable  commercial  use.  The  possibility  of  using  hemlock- 
bark  waste  for  tannin  has  also  been  demonstrated. 

A  commercially  feasible  method  of  recovering  both  the  paraffin  and 
the  fiber  from  waxed  paper  trimmings  has  been  developed.  Studies  of 
the  wastes  incident  to  the  pulp  industries,  such  as  sulphite  waste  liquors 
and  soda  liquors,  in  which  are  now  carried  off  approximately  half  of  the 
wood  that  enters  into  the  digesters,  are  to  be  undertaken  intensively  as 


V 


FOREST  PRODUCTS  LABORATORY. 


Wooden  patterns  for  castings  can  be  made  practically  moisture  proof  by  an  aluminum  leaf  coating  and 
so  prevented  from  warping,  swelling,  or  shrinking.  Car-wheel  patterns  protected  in  this  way  are 
now  in  use  by  several  large  foundries. 


20 


FOREST  PRODUCTS  LABORATORY. 


Old  newspapers  can  be  de-inked  by  the  use  of  bentonite,  a  highly  colloidal  clay,  to  which  the  ink 
particles  adhere  after  being  loosened  from  the  paper  in  the  pulp  beater.  The  pulp  is  then  ready  to 
be  used  again  in  the  manufacture  of  news  paper. 


FOREST  PRODUCTS  LABORATORY.  21 

soon  as  funds  and  equipment  become  available.  The  suitability  for 
paper  making  of  hull  fiber  and  second-cut  cotton  linters,  formerly  of 
little  value,  has  been  demonstrated  and  a  method  of  preparation  worked 
out  that  has  proved  commercially  successful. 

PULP  DECAY. 

A  recently  begun  investigation  of  the  deterioration  of  pulp  wood  and 
wood  pulp  through  fungous  infection,  now  estimated  at  $5,000,000  a  year, 
is  leading  to  the  proper  remedies  for  this  great  economic  loss. 


DERIVED  PRODUCTS. 

HARDWOOD   DISTILLATION. 

The  distillation  of  hardwoods  for  the  production  of  wood  alcohol, 
acetate  of  lime,  and  charcoal  offers  one  of  the  best  methods  for  the  utiliza- 
tion of  hardwood  wastes,  such  as  tops,  limbs,  and  slabs.  The  first  work 
of  the  Laboratory  along  this  line  was  a  study  of  the  comparative  value  of 
different  species  as  distillation  woods — at  that  time  only  beech,  birch,* 
and  maple  were  used  commercially.  All  the  important  hardwoods  have 
been  tested,  and  several  new  species,  such  as  oak  and  hickory,  are  now  in 
use. 

Methods  have  been  developed  whereby  the  yield  of  alcohol  and  acetate 
can  be  considerably  increased  by  a  system  of  temperature  control  with- 
out extending  the  time  of  distillation  and  with  a  decrease  in  the  amount 
of  fuel  required.  These  methods  have  been  adopted  by  most  of  the 
commercial  plants.  Encouraging  results  have  been  obtained  in  work 
now  under  way  on  other  methods  for  increasing  the  yields,  such  as  the 
treatment  of  the  wood  with  chemicals  previous  to  distillation. 

The  production  of  flotation  oils  from  hardwood  tar  is  a  promising 
method  of  utilization  which  has  been  the  subject  of  much  investigation 
of  the  Laboratory.  Several  satisfactory  flotation  oils  have  been  pro- 
duced, and  the  commercial  utilization  of  hardwood  tar  is  increasing. 


22  FOREST    PRODUCTS    LABORATORY. 

TURPENTINE   AND  ROSIX. 

Very  valuable  results  have  been  obtained  by  experimental  field  work 
in  improving  methods  of  obtaining  crude  turpentine  from  the  tree.  A 
new  method  has  been  developed  which  has  increased  the  yield  of  turpen- 
tine and  decreased  the  bad  effect  on  the  tree  and  reduced  the  danger  from 
fire.  This  method  has  been  adopted  by  almost  the  entire  industry.  A 
complete  study  has  also  been  made  of  the  amount  and  composition  of 
the  turpentine  from  several  western  pines.  The  changing  conditions  in 
this  industry  due  to  the  rapid  depletion  of  virgin  stands  of  long-leaf  pine 
make  it  desirable  to  develop  turpentining  methods  which  are  especially 
applicable  to  second-growth  timber  and  to  long-continued  operation  on 
the  same  tree,  instead  of  the  usual  three  to  five  year  operations. 

ETHYL    <  GRAIN)  'ALCOHOL- 

A  promising  method  of  utilizing  profitably  large  quantities  of  wood 
waste  depends  upon  the  conversion  of  the  cellulose  into  ethyl  alcohol.  It 
has  long  been  known  that  wood  cellulose  can  be  converted  into  ferment- 
able sugar  by  suitable  treatment  with  dilute  acids  at  high  pressures,  but 
until  recently  the  process  has  not  met  with  commercial  success.  Inves- 
tigation at  the  Laboratory  involved  the  design  and  installation  of  appa- 
ratus of  semicommercial  size  and  a  detailed  study  of  the  influence  of  such 
variables  as  pressure,  temperature,  time  concentrations  of  acid  and 
water,  and  many  others.  Partly  as  a  result  of  these  experiments  the 
process  is  now  a  commercial  success  and  offers  a  new  means  of  utilization 
which  will  be  a  source  of  heat  and  power  of  immense  economic  importance. 
The  two  plants  now  operating  in  this  country  have  a  combined  daily 
capacity  of  about  9,000  gallons  of  95  per  cent  alcohol.  The  high  quality 
and  purity  of  the  products  are  attested  by  the  great  demand  for  this 
alcohol  for  the  preparation  of  pharmaceuticals  and  colognes. 

SAWDUST   FOR   STOCK   FOOD. 

Another  study  that  has  recently  been  started  is  the  production  of  a 
stock  food  from  sawdust.  As  in  the  manufacture  of  ethyl  alcohol,  the 
cellulose  is  first  converted  into  sugar  by  treatment  under  pressure  with 
dilute  acid,  and  this  sugar,  after  being  extracted  and  boiled  down  to  a 
thick  molasses,  is  mixed  with  the  sawdust  residue.  This  so-called  "  wood 
meal"  has  been  substituted  for  one-fourth  the  ordinary  grain  ration  of 
the  cattle,  with  a  resulting  increase  in  their  weight  and  no  decrease  in 
the  yield  of  milk. 

..OTHER   DERIVED    PRODUCTS. 

Other  products  derived  from  trees  or  forest  materials,  and  therefore 
within  the  scope  of  the  Laboratory's  work,  are  tannins,  gums,  balsams, 
essential  oils  extracted  from  the  wood,  roots,  bark,  or  leaves  of  various 


FOREST  PRODUCTS  LABORATORY. 


Aside  irom  its  value  in  laboratory  tests,  the  determination  of  the  moisture  content  of  wood  is  so  impor- 
tant in  connection  with  the  various  uses  of  wood  that  every  wool  working  factory  should  become 
familiar  with  the  simple  process.  A  knowledge  of  the  moisture  content  of  the  stock  often  makes  it 
possible  to  avoid  costly  manufacturing  difficulties. 


FOREST  PRODUCTS  LABORATORY. 


Special  small-scale  digesters  for  the  manufacture  of  chemical  pulp  provide  facilities  for  the  study  of 
pulping  problems  at  a  moderate  cost,  preliminary  to  a  cooperative  mill  test. 


FOREST  PRODUCTS  LABORATORY.  25 

trees,  and  producer  gas  manufactured  from  wood.  The  chemical  deriv- 
atives of  cellulose,  while  not  yet  touched  upon,  also  offer  a  fertile  field 
for  investigation. 


INDUSTRIAL  INVESTIGATIONS. 

MECHANICAL    UTILIZATION   OF   WASTE   AND  LOW-GRADE    MATERIAL- 

Mechanical  as  well  as  chemical  processes  offer  a  promising  field  for 
the  profitable  utilization  of  wood  now  wasted  and  for  the  steadily 
increasing  amount  of  small  and  low-grade  material  coming  from  second- 
growth  stands.  Only  30  per  cent  of  the  wood  in  a  forest  now  gets  into 
the  form  of  seasoned,  unplaned  lumber.  Of  this,  an  additional  10  to  25 
per  cent  is  lost  in  the  process  of  manufacture.  In  extreme  cases  as  little 
as  3  per  cent  of  the  wood  in  the  forest  may  reach  the  finished  product. 

SURVEY   OF   WOOD   WASTE- 

How  to  reduce  to  a  minimum  these  losses  in  logging  and  manufacture 
constitutes  a  research  problem  of  far-reaching  scope  and  significance. 
The  Laboratory  has  undertaken  a  comprehensive  survey  of  the  present 
practice  and  its  results  in  some  of  the  more  important  wood -using 
industries.  This  will  be  followed  by  more  intensive  investigations  of 
equipment,  methods,  and  processes  with  a  view  to  determining  possible 
modifications  and  improvements.  These  investigations  will  be  con- 
ducted both  in  the  woods  and  at  the  mill  and  will  include  studies  leading 
to  increased  efficiency  of  operation  as  well  as  to  closer  utilization. 

DIMENSION    STOCK. 

The  manufacture  of  small-dimension  stock  offers  a  striking  example 
of  the  opportunity  for  reducing  present  wastes  in  manufacture.  It  has 
been  estimated  that  all  of  the  five  or  six  billion  board  feet  used  each 
year  in  the  manufacture  of  articles  made  from  such  stock  could  be 
secured  from  material  now  wasted.  Whether  or  not  this  is  true,  there 
is  no  question  that  present  wastes  could  be  greatly  reduced  by  standard- 


26 


FOREST  PRODUCTS  LABORATORY. 


The  first  step  in  the  manufacture  of  cattle  food  from  sawdust  is  to  cook  the  sawdust  with  dilute  acid 
in  a  steam-pressure  cylinder.  This  converts  a  part  of  the  wood  into  sugars  and  renders  the  remainder 
more  digestible.  Hydroli/ed  sawdust  is  being  successfully  fed  to  cattle  as  a  considerable  part  of  their 
concentrate  ration. 


FOREST  PRODUCTS  LABORATORY. 


\\  itli  a  microscope  it  i>  possible  to  identify  wood  from  practically  any  of  our  native  trees.     The 
revolving  chart  shows  the  diversity  in  wood  structure  brought  out  under  a  lens. 


28 


FOREST  PRODUCTS  LABORATORY. 


izing  dimension  sizes,  by  cutting  dimension  stock  directly  from  the  log 
instead  of  remanufacturing  it  from  lumber,  and  by  an  interchange 
between  industries  that  would  result  in  the  utilization  by  one  industry 
of  what  is  now  regarded  as  waste  in  another.  Studies  along  these  lines 
have  been  undertaken  by  the  Laboratory  and  will  be  extended  as  rapidly 
as  possible. 

SECOND-GROWTH   STANDS. 

Another  problem  of  first  importance  has  to  do  with  finding  a  profitable 
and  economical  use  for  the  small  sizes  and  low  grades  on  which  we  shall 
have  increasingly  to  depend  as  the  virgin  forests  are  replaced  by  second- 
growth  stands.  This  problem  includes  also  the  finding  of  uses  for  species 
now  without  markets.  To  a  considerable  extent  the  practice  of  forestry 
is  dependent  on  developing  methods  by  which  the  material  of  all  species 
produced  by  these  stands  can  be  used  in  place  of  the  high-grade  material 
of  a  few  species  from  virgin  forests  to  which  we  have  hitherto  been 
accustomed.  This  involves  not  only  perfecting  the  technique  of  built-up 
and  laminated  construction,  but  the  introduction  of  new  uses  and  new 
methods  of  manufacture.  Investigation  of  these  and  related  problems 
will  go  far  toward  enabling  us  to  eliminate  present  wastes  and  to  make 
the  most  of  our  wood  supply. 


PATHOLOGY. 

The  work  of  this  section  is  conducted  by  the  Bureau  of  Plant  Industry 
of  the  Department  of  Agriculture.  General  studies  of  the  durability  and 
decay  of  wood  are  carried  on. 

DURABILITY   OF   UNTREATED   WOOD. 

The  relative  durability  of  different  woods  and  the  effects  of  moisture 
and  wood-destroying  fungi  upon  the  life  of  the  wood  have  been  studied 
for  many  kinds  of  American  woods.  Data  have  been  obtained  upon  the 
least  and  most  favorable  temperatures  for  the  growth  of  fungi  and  the 
amount  of  heat  required  to  stop  their  growth.  An  application  of  this 
work  is  the  control  of  so-called  "dry  rot"  in  buildings. 


FOREST  PRODUCTS    LABORATORY.  29 

DECAY   IN   BUILDING  TIMBER. 

Extensive  investigations  to  determine  the  prevalence  of  decay  in 
buildings  throughout  the  United  States  have  been  made,  and  from  in- 
formation collected  over  a  lo-year  period  recommendations  have  been 
developed  as  to  changes  in  architectural  design,  proper  species  for 
different  uses,  and  suitable  antiseptic  treatments. 

SANITATION   OF    STORAGE   YARDS. 

Unsuspected  losses  by  wood  users  resulting  from  improper  storage  of 
wood  aggregate  several  million  dollars  annually.  Studies  and  recom- 
mendations have  been  made  on  storage  of  general  lumber  stocks  at 
sawmills  and  retail  yards,  the  storage  of  manufactured  wood  products, 
such  as  vehicle  parts,  boxwoods,  veneers,  and  staves,  and  also  the  storage 
of  pulp  w^ood  and  pulp.  Infection  begun  in  the  yard  frequently  is 
passed  on  in  the  manufactured  product  to  other  wood  with  which  the 
infected  material  is  used. 


HOW  TO  USE  THE  LABORATORY. 

INFORMATION   FREE. 

The  Laboratory,  being  a  public  institution,  makes  its  information 
available  to  the  public  as  rapidly  as  possible.  This  it  does  through 
personal  contact  and  through  reports  written  during  the  progress  of 
investigation  and  upon  their  completion,  so  that  all  information  of  value 
is  published,  either  as  bulletins  or  circulars  by  the  Government,  in 
technical  notes,  by  correspondence,  or  as  special  articles  in  trade  journals 
and  technical  and  scientific  papers. 

Investigations  are  undertaken  both  independently  and  on  a  coopera- 
tive basis,  but  all  investigations  must  be  of  a  research  character  that  will 
give  information  or  results  of  value  in  attaining  the  general  objects  aimed 
at  by  the  Laboratory. 


FOREST  PRODUCTS  LABORATORY. 


Classes  in  boxing  and  crating  at  the  laboratory  make  use  of  the  i4-foot  drum  'testing  machine  to 
investigate  the  serviceability  of  shipping  boxes.  The  manufacturers  and  shippers  in  the  group 
traveled  an  average  of  ?,ooo  miles  each  to  attend  the  one-week  course 


FOKKST  PRODUCTS  LABORATORY'.  31 

COOPERATION. 
• 
As  a  general  rule,  no  investigation  conducted  by  the  Laboratory  is 

regarded  as  complete  until  the  results  obtained  experimentally  have  been 
checked  on  a  commercial  scale  and  their  industrial  application  deter- 
mined. This  is  ordinarily  accomplished  through  cooperation  with  in- 
dividuals or  companies  that  use  wood  and  are  commercially  interested 
in  developing  new  or  better  processes  or  products. 

FORMAL    COOPERATION   AT   EXPENSE   OF    COMPANY. 

In  cases  of  formal  cooperation,  there  should  be  a  remuneration  to  the 
Laboratory  depending  on  the  cost  of  the  work  done  for  the  cooperator, 
including  the  time  and  expense  of  the  members  of  the  Laboratory  de- 
tailed to  the  project,  and  its  general  supervision.  When  practically  all 
of  the  work  proposed  is  investigative  and  the  results  of  value  chiefly  to 
the  general  public,  the  charge  to  the  cooperator  may  be  comparatively 
low  or  eliminated  altogether. 

CONSULTATION   ON    SPECIAL    PROBLEMS. 

Anyone  is  at  liberty  to  correspond  with  the  Laboratory  about  particu- 
lar problems  dealing  with  the  utilization  of  wood  and  will  receive  answers 
based  on  whatever  information  is  available  on  the  subject.  The  staff 
of  the  Laboratory  is  also  available  for  consultation  work,  provided  the 
solution  of  the  problem  under  consideration  will  further  its  general 
research  work,  or  has  direct  bearing  upon  it. 

Personal  visits  to  the  Laboratory  for  consultation  have  proved  very 
satisfactory. 

The  Laboratory  may,  on  request,  examine  the  methods  of  individuals 
or  companies  used  in  handling  forest  products  and  prepare  plans  for 
improving  such  methods,  provided  that  the  purpose  is  primarily  to 
reduce  waste  and  to  obtain  information  of  general  value  to  the  indus- 
tries concerned. 

COURSES  OF   INSTRUCTION. 

Two  short  cooperative  courses  of  instruction  are  given  monthly  at  the 
Laboratory — one  in  kiln-drying,  the  other  in  boxing  and  crating.  These 
courses  are  of  particular  value  to  superintendents,  lumber  and  produc- 
tion men,  and  foremen  in  wood-using  plants.  The  instruction  is  under 
the  supervision  of  a  staff  of  competent  specialists  and  the  enrollment  is 
limited  to  16  men  in  each  course,  so  that  proper  attention  may  be  given 
to  individual  problems.  Priority  of  application  governs  admission  to 
the  courses,  and  the  classes  are  usually  filled  for  two  or  three  months 
ahead. 

Detailed  information  concerning  any  of  the  work  of  the  Laboratory 
will  be  gladly  furnished.  Inquiries  should  be  addressed  to  the  Director, 
Forest  Products  Laboratory,  Madison,  Wis. 

o 


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